Multi-Camera Array with Shared Spherical Lens

ABSTRACT

Multiple cameras are arranged in an array at a pitch, roll, and yaw that allow the cameras to have adjacent fields of view such that each camera is pointed inward relative to the array. The read window of an image sensor of each camera in a multi-camera array can be adjusted to minimize the overlap between adjacent fields of view, to maximize the correlation within the overlapping portions of the fields of view, and to correct for manufacturing and assembly tolerances. Images from cameras in a multi-camera array with adjacent fields of view can be manipulated using low-power warping and cropping techniques, and can be taped together to form a final image.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.14/921,410, filed Oct. 23, 2015, which is a continuation of U.S.application Ser. No. 14/308,501, filed Jun. 18, 2014, now U.S. Pat. No.9,196,039, which claims the benefit of U.S. Provisional Application No.61/973,788, filed Apr. 1, 2014, U.S. Provisional Application No.61/979,386, filed Apr. 14, 2014, and U.S. Provisional Application No.61/985,256, filed Apr. 28, 2014, all of which are incorporated byreference herein in their entirety.

TECHNICAL FIELD

This disclosure relates to a camera array and, more specifically, tomethods for capturing images using the camera array.

BACKGROUND

Digital cameras are increasingly used in outdoors and sportsenvironments. Using a camera to capture outdoors and sportsenvironments, however, can be difficult if the camera is bulky or cannotcapture the field of view desired. A user's experience with a camera canbe diminished by camera bulkiness and limited camera functionality.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The disclosed embodiments have other advantages and features which willbe more readily apparent from the following detailed description of theinvention and the appended claims, when taken in conjunction with theaccompanying drawings, in which:

FIG. 1A illustrates a conventional multiple camera system, according toone embodiment.

FIG. 1B illustrates a 2×1 camera array arranged according to oneembodiment of the configurations described herein.

FIG. 2 illustrates roll, pitch, and yaw rotations of a camera in acamera array, according to one embodiment.

FIG. 3 illustrates a 2×2 camera array arranged according to oneembodiment of the configurations described herein.

FIG. 4A illustrates a conventional multi-part camera frame, according toone embodiment.

FIG. 4B illustrates a single-body camera frame, according to oneembodiment.

FIG. 5 illustrates a block diagram of a multiple camera array, accordingto one embodiment.

FIG. 6 illustrates a block diagram of a synchronization interface for amultiple camera array, according to one embodiment.

FIG. 7A illustrates a read window adjustment for each image sensor in amultiple camera array for tolerance compensation, according to oneembodiment.

FIG. 7B illustrates unaligned read windows within image sensor capturewindows of a multiple camera array, according to one embodiment.

FIG. 7C illustrates aligned read windows within image sensor capturewindows of a multiple camera array, according to one embodiment.

FIG. 7D illustrates a distance of optimal correlation between imagesensors of a multiple camera array.

FIGS. 8A-8C illustrates a read window adjustment for each image sensorin a multiple camera array for convergence point adjustment, accordingto one embodiment.

FIG. 9A illustrates a set of images captured by cameras in a 2×2 cameraarray, according to one embodiment.

FIG. 9B illustrates the images of FIG. 9A aligned based on overlappingportions, according to one embodiment.

FIG. 9C illustrates the aligned images of FIG. 9B cropped to removeexcess portions not horizontally or vertically aligned withcorresponding adjacent images, according to one embodiment.

FIG. 9D illustrates the cropped images of FIG. 9C warped to correct fordistortions based on the alignment, according to one embodiment.

FIG. 9E illustrates the corrected images of FIG. 9D cropped to removeexcess portions and overlapping portions, according to one embodiment.

FIG. 10A illustrates a distance between two lens modules in a multiplecamera array, according to one embodiment.

FIG. 10B illustrates a ball lens for use in a multiple camera array,according to one embodiment.

FIG. 11A illustrates a camera body configured to receive a multiplecamera array in a plurality of configurations, according to oneembodiment.

FIG. 11B illustrates a multiple camera array module for insertion withina camera body in a plurality of configurations, according to oneembodiment.

FIG. 12A illustrates a camera strap including a battery system and anassociated electrical interface, according to one embodiment.

FIG. 12B illustrates a camera strap including a battery interfacesystem, according to one embodiment.

FIG. 12C illustrates the camera strap of FIG. 12A, according to oneembodiment.

FIG. 13 illustrates a grip system for a camera system, according to oneembodiment.

FIG. 14A illustrates adjacent lens stacks in a multiple camera array,according to one embodiment.

FIG. 14B illustrates adjacent lens stacks including cone lenses in amultiple camera array, according to one embodiment.

DETAILED DESCRIPTION

The figures and the following description relate to preferredembodiments by way of illustration only. It should be noted that fromthe following discussion, alternative embodiments of the structures andmethods disclosed herein will be readily recognized as viablealternatives that may be employed without departing from the principlesof what is claimed.

Reference will now be made in detail to several embodiments, examples ofwhich are illustrated in the accompanying figures. It is noted thatwherever practicable similar or like reference numbers may be used inthe figures and may indicate similar or like functionality. The figuresdepict embodiments of the disclosed system (or method) for purposes ofillustration only. One skilled in the art will readily recognize fromthe following description that alternative embodiments of the structuresand methods illustrated herein may be employed without departing fromthe principles described herein.

Example 2×1 and 2×2 Camera Array Configuration

A camera array configuration includes a plurality of cameras, eachcamera having a distinctive field of view. For example, the camera arraycan include a 2×1 camera array, a 2×2 camera array, or any othersuitable arrangement of cameras. Each camera can have a camera housingstructured to at least partially enclose the camera. Alternatively, thecamera array can include a camera housing structured to enclose theplurality of cameras. Each camera can include a camera body having acamera lens structured on a front surface of the camera body, variousindicators on the front of the surface of the camera body (such as LEDs,displays, and the like), various input mechanisms (such as buttons,switches, and touch-screen mechanisms), and electronics (e.g., imagingelectronics, power electronics, etc.) internal to the camera body forcapturing images via the camera lens and/or performing other functions.In another embodiment, the camera array includes some or all of thevarious indicators, various input mechanisms, and electronics andincludes the plurality of cameras. A camera housing can include a lenswindow structured on the front surface of the camera housing andconfigured to substantially align with the camera lenses of theplurality of cameras, and one or more indicator windows structured onthe front surface of the camera housing and configured to substantiallyalign with the camera indicators.

FIG. 1A illustrates a conventional multiple camera environment 100,according to one embodiment. In the embodiment, the conventional cameraenvironment 100 includes two cameras 105A and 105B. In this environment100, the camera 105A is used to capture a left side (e.g., field of view108A) of a shared view 115 as the image 110A and the camera 105B is usedto capture a right side (field of view 108B) of the shared view 115 asthe image 110B. A portion of the field of view 108A of the left camera105A and a portion of the field of view 108B of the right camera 105Brepresent a common field of view, as illustrated by the shaded portionof the shared view 115. The common field of view includes a cube and asphere. Based on the shared portions of images 110A and 110B, the images110A and 110B can be taped together to form a single flat image of theshared view 115.

Even though cameras 105A and 105B have a partial common field of view,any object in the common field of view may not be aligned in imagescaptured by the left camera 105A and the right camera 105B. Thus, asseen in the left image 110A, a part of the sphere appears to the left ofthe cube and, in the right image 110B, a part of the sphere appears tothe right of the cube. This offset 120 of the cube and sphere are due toparallax error. The parallax error is inherent to the conventionalcamera environment 100 because the distance between the cameras causesthe position of objects in the common field of view to be differentrelative to each to each camera, based on the distance between thecameras. Parallax error can be further exacerbated based on a positionof a read window 130 of an image sensor window 140 of an image sensorwithin each camera. For example, the read window 130 is not necessarilycentered on the image sensor window 140 and, therefore, can result in agreater effective distance the cameras 105A and 105B. The position ofthe read window 130 within an image sensor window 140 is an issue thatcan arise during the manufacturing of the image sensor and can beadjusted for various purposes, as further described in FIGS. 7 and 8.

FIG. 1B illustrates a 2×1 camera array arranged according to oneembodiment of the configurations described herein. In the embodiment,the 2×1 camera array 150 includes two cameras 105C and 105D. In anotherembodiment, as illustrated and described further in conjunction withFIG. 3, two 2×1 camera arrays 150 are combined to form a 2×2 cameraarray 150 that includes four cameras. In this array 150, the camera 105Ccaptures a left side (e.g., field of view 108C) of the shared view 115and the camera 105D captures a right side (e.g., field of view 108D) ofthe shared view 115. However, the left camera 105C captures an image110C of the right side of the shared view 115 and the right camera 105Dcaptures an image 110D of the left side of the shared view. The leftcamera 105C and right camera 105D have a partial common field of view,as illustrated in the shaded portion of array 150. However, the partialcommon field of view in FIG. 1B has a different shape than the partialcommon field of view in FIG. 1A. The partial common field of view sharedby cameras 105C and 105D includes a cube and a sphere. Based on theshared portions of images 110C and 110D, the images 110C and 110D can betaped together to form a single angled image of the shared view 115.

The angled image formed by taping the images 110C and 110D together isdifferent than the flat image formed by taping the images 110A and 110Btogether in FIG. 1A. The 2×1 camera array 150 captures images at fieldsof view that are not parallal, as is the case for the array 100 in FIG.1A, but instead captures images at fields of view that are angled withrespect to each other. The angled image is a result of the configurationof the cameras in the 2×1 camera array 150 as further described inconjunction with FIGS. 2 and 3. Correction of the angled image of theshared view 115 to simulate images captured with parallel fields of viewis described further in conjunction with FIG. 9.

Unlike the environment 100 in FIG. 1A, the positioning of the camerawithin the array 150 of FIG. 1B allows both cameras 105C and 105D toshare a portion of the other camera's field of view while minimizingparallax error of any object in the shared portion captured by thecameras 105C and 105D. For instance, the left image 110C includes asmaller portion of the sphere that appears on the left of the cube thanleft image 110A, and the right image 110D includes a smaller portion ofthe sphere that appears on the right of the cube than right image 110B.For example, the offset 160 of the left image 110C can be 1-3 pixelswhen capturing objects within 3 meters of the 2×1 camera array 150. The2×1 camera array 150 minimizes distance between the cameras 105A and105B, minimizing parallax error. For example, the distance between thecameras 105C and 105D (measured from the center of each camera lens) canbe between 1 mm and 60 mm.

It should be noted that the orientation of cameras 105C and 105D is suchthat the vectors normal to each camera lens of cameras 105C and 105Dintersect within the partial common field of view. In contrast, whilethe cameras 105A and 105B have a partial common field of view, vectorsnormal to each camera lens of cameras 105A and 105B do not intersectwithin the partial common field of view. In embodiments with a 2×2camera array, vectors normal to each camera lens in the array canintersect within a field of view common to all cameras. For example, forany two cameras, vectors normal to the camera lenses of the two camerascan intersect within a field of view common to all four cameras.

FIG. 2 illustrates roll, pitch, and yaw rotations of a camera in acamera array, according to one embodiment. For example, when minimizingdistance between cameras in a camera array, a camera can be rotated inthree dimensions: roll 210, pitch 220, and yaw 230. By rotating a camerain these three dimensions to minimize distance between lenses of thecamera with another camera, the shared view 115 being captured by eachof a plurality of cameras can be captured at tilted, angled, or rotatedfields of view. The captured images of the shared view 115 with thetilted, angled, and rotated fields of view can be corrected using imageprocessing as described further in conjunction with FIG. 9.

The camera 105 illustrated in FIG. 2 has a roll 210 rotation in a rangeof 30−50°, a yaw 230 rotation in a range of 60−80°, and a pitch 220rotation of 60-80°. The direction of each rotation (i.e., roll 210, yaw230, pitch 220) of the camera 105 depends on the position of the camera105 in the array. For example, if the camera 105 was in the top left ofa camera array, as illustrated in FIG. 2, the camera 105 would have anegative roll rotation, a negative yaw rotation, and a negative pitchrotation, wherein direction is respective to the arrows illustrated inFIG. 2. If the camera 105 was in the top right of a camera array, thecamera 105 would have a positive roll rotation, a positive yaw rotation,and a negative pitch rotation. If the camera 105 was in the bottom leftof a camera array, the camera 105 would have a positive roll rotation, anegative yaw rotation, and a positive pitch rotation. If the camera 105was in the bottom right of a camera array, the camera 105 would have apositive roll rotation, a positive yaw rotation, and a positive pitchrotation. The directions of rotations 210, 220, and 230 can also bebased on the shape of the camera 105, as further described inconjunction with FIG. 4. However, in general, the directions of therotations 210, 220, and 230 are determined to minimize distances betweenthe lenses of the array to a range of, for example, 1 mm-5 mm, asfurther described in conjunction with FIG. 3. It should be noted inother embodiments, each camera 105 can be oriented at a different roll,yaw, and pitch than described herein.

FIG. 3 illustrates a 2×2 camera array arranged according to oneembodiment of the configurations described herein. The 2×2 camera array300 includes four cameras 105A, 105B, 105C, and 105D. Each camera has aroll rotation, a pitch rotation, and a yaw rotation, the rotationsminimizing distance 310 between centers of the lenses, as indicated bythe dashed lines 320, to be within a range of, for example, 1 mm to 10mm. The cameras 105A-D in the illustrated 2×2 camera array 300 eachcapture an angled image of a shared view of the 2×2 camera array 300. Inother words, each camera captures an image of a corresponding field ofview, and the corresponding field of views of the cameras overlap butare not parallel. The camera 105A captures the bottom left portion ofthe shared view, the camera 105B captures the bottom right portion ofthe shared view, the camera 105C captures the top left portion of theshared view, and the camera 105D captures the top right portion of theshared view. As used herein, “shared view” refers to each of thecorresponding fields of view of the cameras 105A-D of the 2×2 cameraarray 300.

The camera array 300 can be adapted to be at least partially enclosed bya protective camera housing (not illustrated in the embodiment of FIG.3). In one embodiment, the camera array 300 and/or housing of the array300 has a small form factor (e.g., a height of approximately 1 to 6centimeters, a width of approximately 1 to 6 centimeters, and a depth ofapproximately 1 to 2 centimeters), and is lightweight (e.g.,approximately 50 to 150 grams). The housing and/or camera bodies can berigid (or substantially rigid) (e.g., plastic, metal, fiberglass, etc.)or pliable (or substantially pliable) (e.g., leather, vinyl, neoprene,etc.). In one embodiment, the housing and/or the array may beappropriately configured for use in various elements. For example, thehousing may include a waterproof enclosure that protects the cameraarray 300 from water when used, for example, while surfing or scubadiving. In some embodiments, such as those described below, the cameraarray can 300 can be secured within a protective multiple camera arraymodule, which in turn can be secured within a camera body in one or moreorientations.

Portions of the housing and/or array may include exposed areas to allowa user to manipulate buttons that are associated with the camera array300 functionality. Alternatively, such areas may be covered with apliable material to allow the user to manipulate the buttons through thehousing. For example, in one embodiment the top face of the housingincludes an outer shutter button structured so that a shutter button ofthe camera array 300 is substantially aligned with the outer shutterbutton when the camera array 300 is secured within the housing. Theshutter button of the camera array 300 is operationally coupled to theouter shutter button so that pressing the outer shutter button allowsthe user to operate the camera shutter button.

In one embodiment, the front face of the housing includes one or morelens windows structured so that the lenses of the cameras in the cameraarray 300 are substantially aligned with the lens windows when thecamera array 300 is secured within the housing. The lens windows can beadapted for use with a conventional lens, a wide angle lens, a flatlens, or any other specialized camera lens. In this embodiment, the lenswindow includes a waterproof seal so as to maintain the waterproofaspect of the housing.

In one embodiment, the housing and/or array includes one or moresecuring structures for securing the housing and/or array to one of avariety of mounting devices. For example, various mounts include aclip-style mount or a different type of mounting structure via adifferent type of coupling mechanism.

In one embodiment, the housing includes an indicator window structuredso that one or more camera array indicators are substantially alignedwith the indicator window when the camera array 300 is secured withinthe housing. The indicator window can be any shape or size, and can bemade of the same material as the remainder of the housing, or can bemade of any other material, for instance a transparent or translucentmaterial and/or a non-reflective material.

The housing can include a first housing portion and a second housingportion, according to one example embodiment. The second housing portiondetachably couples with the first housing portion opposite the frontface of the first housing portion. The first housing portion and secondhousing portion are collectively structured to enclose a camera array300 within the cavity formed when the second housing portion is securedto the first housing portion in a closed position.

The camera array 300 is configured to capture images and video, and tostore captured images and video for subsequent display or playback. Thecamera array 300 is adapted to fit within a housing, such as the housingdiscussed above or any other suitable housing. Each camera 105A-D in thearray 300 can be an interchangeable camera module. As illustrated, thecamera array 300 includes a plurality of lenses configured to receivelight incident upon the lenses and to direct received light onto imagesensors internal to the lenses.

The camera array 300 can include various indicators, including LEDlights and a LED display. The camera array 300 can also include buttonsconfigured to allow a user of the camera array 300 to interact with thecamera array 300, to turn the camera array 300 on, and to otherwiseconfigure the operating mode of the camera array 300. The camera array300 can also include a microphone configured to receive and record audiosignals in conjunction with recording video. The camera array 300 caninclude an I/O interface. The I/O interface can be enclosed by aprotective door and/or include any type or number of I/O ports ormechanisms, such as USC ports, HDMI ports, memory card slots, and thelike.

The camera array 300 can also include a door that covers a removablebattery and battery interface. The camera array 300 can also include anexpansion pack interface configured to receive a removable expansionpack, such as a display module, an extra battery module, a wirelessmodule, and the like. Removable expansion packs, when coupled to thecamera array 300, provide additional functionality to the camera array300 via the expansion pack interface.

FIG. 4A and FIG. 4B illustrate a conventional multi-part camera frame405A and a single-body camera frame 405B, respectively, according to oneembodiment. The conventional multi-part camera frame 405A includes aplurality of lenses 410, an image sensor 415, and auto-focus coils 420.In order to enclose all the components 410, 415 and 420, the frame 405Ahas a square profile, as illustrated in FIG. 4A. The conventionalmulti-part camera frame 405A limits the proximity of the center oflenses of two adjacent multi-part camera frames 405A.

A single-body camera frame 405B can be used to improve proximity of thecenter of lenses of adjacent camera frames. The single-body camera frame405B (also referred to herein as a “lens stack”) includes the pluralityof lenses 410 and the image sensor 415 but does not include theauto-focus coils 420. In addition, the single-body camera frame 405B isa single mold that holds the components 410 and 415 within the frame405B in a fixed position, set by the mold, and minimizes excess spacewithin the frame 405B. The cross-section of the frame 405B istrapezoidal in shape, allowing adjacent cameras to be configured suchthat the proximity between the centers of the lenses of the cameras isreduced. In some embodiments, for lenses that are approximately 1 mm indiameter, the distance between the centers of the lenses of adjacentcameras is 1 mm or less.

Camera Array Block Diagrams

FIG. 5 illustrates a block diagram of a multiple camera array, accordingto one embodiment. The array 300 includes four cameras 500A, 500B, 500C,and 500D, for example of cameras 105A, 105B, 105C, and 105D of FIG. 3,and each camera includes an image sensor 510, a sensor controller 515, aprocessor 520, and memory 525. In another embodiment, the four cameras500A, 500B, 500C, and 500D can have image sensors that share a commonprocessor 520, and memory 525. The synchronization interface 505synchronizes the four cameras 500A, 500B, 500C, and 500D tosynchronously capture images. In various embodiments, the cameras 500A,500B, 500C, and 500D can include additional, fewer, or differentcomponents for various applications. As used herein, the synchronouscapture of images refers to the capture of images by two or more camerasat substantially the same time, or within a threshold period of time.

The image sensor 510 is a device capable of electronically capturinglight incident on the image sensor 510. In one embodiment, CMOS sensorsare used, including transistors, photodiodes, amplifiers,analog-to-digital converters, and power supplies. In one embodiment, theimage sensor 510 has rolling shutter functionality, and can capturelight incident upon different portions of the image sensor at slightlydifferent times. Alternatively, the image sensor 510 can be a CCD sensorconfigured to can capture the portions of the image at substantially thesame time. In one embodiment, the image sensor 510 has an adjustableread window 130. An adjustable read window 130 can modify the portionsof an image sensor that are exposed to light and read to capture animage, or can modified the portions of an image sensor completelyexposed to light that are read out to capture an image. By adjusting theread window 130, the camera 500A can modify when a portion of an imageis captured relative to when image capture begins. For example, byshifting the read window 130 in a rolling shutter direction, the imagesensor captures portions of the image in the read window 130 earlierthan if the read window 130 was not shifted in the rolling shutterdirection. Additionally, adjusting the read window 130 can be used toaddress inherent tolerance issues with the camera 500A and adjustconvergence point of the camera array, as further described inconjunction with FIGS. 7 and 8.

The processor 520 is one or more hardware devices (e.g., a centralprocessing unit (CPU), a graphics processing unit (GPU), a digitalsignal processor (DSP), and the like) that execute computer-readableinstructions stored in the memory 525. The processor 520 controls othercomponents of the camera based on the instructions that are executed.For example, the processor 520 may send electronic control signals tothe image sensor 510 or use the synchronization interface 505 to senddata to cameras 500B, 500C, and 500D.

The memory 525 is a non-transitory storage medium that can be read bythe processor 520. The memory 525 may contain volatile memory (e.g.,random access memory (RAM)), non-volatile memory (e.g., a flash memory,hard disk, and the like), or a combination thereof. The memory 525 maystore image data captured by the image sensor 510 and computer-readableinstructions to be executed by the processor 520.

The sensor controller 515 controls operation of the image sensor 510 andother functions of the camera 500A. The sensor controller 515 caninclude physical and/or electronic input devices, such as exteriorbuttons to start recording video and/or capture a still image, atouchscreen with tap-to-focus capabilities, and a dial/buttoncombination for navigating a menu hierarchy of the camera 500A. Inaddition, the sensor controller 15 may include remote user inputdevices, such as remote controls that wirelessly communicate with thecameras 500A-D. The image sensor 510 may function independently of thesensor controller 515. For example, a slave camera in a master-slavepairing can receive a signal from the master camera to capture an imagethrough the synchronization interface 505.

The synchronization interface 505 sends data to and receives data fromcameras 500A, 500B, 500C, and 500D, or an external computing system. Inparticular, the synchronization interface 505 may send or receivecommands to cameras 500A, 500B, 500C, and 500D for simultaneouslycapturing an image and/or calibrating synchronization with the cameras500A, 500B, 500C, and 500D (e.g., sending or receiving a synchronizationpulse). In the illustrated embodiment of FIG. 5, there is onesynchronization interface 505 controlling the cameras 500A, 500B, 500C,and 500D. In another embodiment, there can be a plurality ofsynchronization interfaces 505 controlling the cameras 500A-D, forinstance, one synchronization interface 505 per camera.

FIG. 6 illustrates a block diagram of a synchronization interface for amultiple camera array, according to one embodiment. The synchronizationinterface 505 includes an image store 605, a synchronization store 610,a capture controller 615, a pixel shift determination module 620, a timelag determination module 625, and an image capture module 630. Alternateembodiments may have one or more additional, omitted, or alternativemodules configured to perform similar functionality. It should be notedthat in other embodiments, the modules described herein can beimplemented in hardware, firmware, or a combination of hardware,firmware, and software. In addition, in some embodiments, a first camerain a plurality of cameras includes the components illustrated in FIG. 6,while the other cameras in the plurality of cameras do not necessarilyinclude the components of FIG. 6 and instead merely synchronouslycapture an image in response to a signal from the first camera. As usedherein, a “plurality of images” refers to a plurality of images capturedsynchronously by the plurality of cameras, each camera capturing aportion of a field of view shared with two adjacent cameras.Alternatively or additionally, an external computing device processesimage data captured by the camera array.

The image store 605 is configured to store a plurality of imagessynchronously captured by each of a plurality of cameras, such as thecameras 500A-D of FIG. 5. The synchronization store 610 is configured tostore received camera synchronization data. Examples of synchronizationdata include time lags between cameras due to network lag or internalcomponent lag (e.g., lag from the synchronization interface 505, theprocessor 520, the sensor controller 515, and the like). Thesynchronization store 610 is configured to store calibration settings,such as read window shift information and a calibrated time lag forinitiating image capture, for use in calibrating the cameras in a cameraarray based on, for example, camera synchronization data.

The capture controller 615 controls image capture by the image sensor510. In one embodiment, the capture controller 615 applies a calibrationcorrection to synchronize image capture with one or more additionalcameras, for instance based on synchronization or calibration datastored in the synchronization store 610. The calibration correction mayinclude a read window shift by a determined number of pixels, asdetermined by the pixel shift determination module 620. The calibrationcorrection may include, alternatively or additionally, a time lag forone of the cameras in the array to delay relative to the other camera ofthe array before beginning image capture, as determined by the time lagdetermination module 625.

The pixel shift determination module 620 identifies a pixel shiftbetween an image captured by a first camera 500A, an image captured by asecond camera 500B, an image captured by a third camera 500C, and animage captured by a fourth camera 500D. This pixel shift indicatesspatial misalignment between the image sensors of the cameras 500. Inone embodiment, the pixel shift determination module 620 determines apixel shift in a rolling shutter direction due to a misalignment betweenthe image sensors along the rolling shutter direction. The capturecontroller 615 can use the determined pixel shift to correct themisalignment between the image sensors.

The time lag determination module 625 determines a time lag between thecapture of an image row by a first camera 500A, a corresponding imagerow of a second camera 500B, a corresponding image row of a third camera500C, and a corresponding image row of a fourth camera 500D. The timelag determination module 625 can determine a time lag based on a pixelshift received from the pixel shift determination module 620. Using thedetermined time lag, t_(lag), the capture controller 615 synchronizesthe plurality of cameras by delaying image capture of a first of theplurality by the time lag relative to a second, third and fourth of theplurality. In one embodiment, an image sensor has an associated rowtime, t_(row), which represents an elapsed time between exposing a firstpixel row and a second, subsequent pixel row. If images taken by aplurality of cameras are determined to have a pixel shift of n pixels,then the time lag t_(tag) required to correct the pixel shift can bedetermined using the following equation:

t _(lag) =t _(row) ×n

In one embodiment, calibrating image capture between cameras in aplurality of cameras involves synchronously capturing images with theplurality of cameras, determining a pixel shift between the capturedimages, and applying a determined correction iteratively until thedetermined pixel shift is less than a pre-determined pixel shiftthreshold. The calibration process may be initiated when cameras arepowered on or paired, when the cameras are manufactured, when the cameraarray is assembled, or in response to a manual initiation of thecalibration process by a user of the camera array. A master camerasystem can initiate the calibration process after an amount of timeelapses that is greater than or equal to a pre-determined thresholdsince a previous calibration. In an embodiment with additional cameras,additional calibrations can be performed among other cameras in responseto the calibration of the master camera.

The image capture module 630 processes captured images. In analternative embodiment not described further herein, the captured imagesare processed outside of the synchronization interface 505, for instanceby a system external to the camera array. The image capture module 630includes a tolerance correction module 632, a convergence adjustmentmodule 634, and an image processing module 636. Alternative embodimentsmay have one or more additional, omitted, or alternative modulesconfigured to perform similar functionality.

The tolerance correction module 632 shifts read windows of the pluralityof cameras 500 to correct for tolerances in each camera in theplurality. For example, each camera can have slight differences in readwindow location due to manufacturing discrepancies and producttolerances of the cameras. In addition, image sensors of the pluralityof cameras can have varying read window locations. These variations fromcamera to camera can be due to discrepancies between locations andorientations of the image sensor within each camera. For example, if theimage sensor is a complementary metal-oxide-semiconductor (CMOS) sensor,the location of the read window for each CMOS sensor can shift due tothe sensitivity of pixel sensors used in each CMOS sensor. Shifted readwindow locations in CMOS sensors of cameras in the camera array canshift the field of views of cameras, as shown in the field of views ofcameras in the camera array 700 in FIG. 7A. This can result in a shiftedshared field of view (e.g., shaded portion unaligned with the field ofviews of the cameras in the camera array 700). For example, thetolerance correction module 632 can recognize a shift in read windowlocations based on outputs of pixel sensors in the read windows. Theoutputs of image sensors in a first region of a first camera and asecond region of a second camera, where the first region and the secondregion overlap, can be compared, and the location of the read window ofan image sensor of the first camera, the second camera, or both can beshifted based on the comparison. For instance, upon comparingoverlapping image sensor regions, if a determination is made that afirst of the regions is offset from a second of the regions by adetermined number of pixels, the first region or the second region canbe shifted by the number of pixels (for instance, by adjusting alocation of the read window on an image sensor by the number of pixels)to align the regions. The process of correcting for tolerance of thecameras 500 is further described below in conjunction with FIG. 7.

The convergence adjustment module 634 can dynamically adjust a readwindow in an image sensor based on image data captured by the cameraarray. For example, if the camera array is capturing an image of anobject in a foreground, the convergence point of the plurality ofcameras in the camera array can be adjusted closer to the camera arrayand, if capturing an object in a background, the convergence point ofthe plurality of cameras in the camera array can be adjusted fartheraway from the camera array. In another example, the convergence point ofthe camera array is only adjusted by the convergence adjustment module634 if the depth of the object in the field of view of the camera arrayexceeds a threshold distance. The convergence adjustment can be donemanually by a user of the camera array or automatically by theconvergence adjustment module 634 based on image processing algorithmsmeasuring a depth of an object in the field of view of the camera array.The process of adjusting convergence of the plurality of cameras 500 isfurther described in conjunction with FIG. 8.

The image processing module 636 adjusts images captured by the cameraarray to compensate for the angled fields of view of the cameras of thecamera array. The images are adjusted using, for example warps,transformations, crops, or any other suitable image enhancement,restoration, and/or compression techniques. One or more of the imagescan be adjusted individually, or all of the images can be adjustedsubstantially synchronously or sequentially. For example, prior to andduring the taping of the images to produce a simulated flat image, asfurther described below in conjunction with FIG. 9.

Read Window Adjustment

FIG. 7A illustrates a read window adjustment for each image sensor in amultiple camera array for tolerance compensation, according to oneembodiment. For example, illustrated is an imperfectly aligned 2×1camera array 700 illustrated in the shaded area misaligned with thelines representing the common field of view of the cameras in the cameraarray 700. A portion of each of the fields of view of cameras 705A and705B is common to both fields of view, and includes a cube. However,images 710A and 710B captured by the cameras 705A and 705B,respectively, illustrate that the cube is not aligned on the x-axis ory-axis of the read windows of the image sensors in the cameras 705.

In the illustrated example, the images 710A and 710B display the cornerof the cube at (x,y) coordinates (3,4) and (12,6), respectively, wherethe read window has a height of 12 pixels and 20 pixels and the cube awidth of 3 pixels. Thus, the cube has different heights within the readwindows, and has different locations along the x-axis within the readwindows. The read window of the image sensor of each camera in theplurality of cameras 705A and 705B can be adjusted to display the centerof the cube at the same height in the y-axis and distance from therespective edges in the x-axis. Images 710C and 710D illustrate adjustedread windows, showing the corner of the cube displayed at (4,5) and(13,5), respectively (a same height and distance from the image edge).Detection of the cube can be an automatic process based on an objectdetection algorithm or assisted by a user of the camera array 700 andthe user's input.

FIG. 7B illustrates unaligned read windows 130 within image sensorwindows 140 of a multiple camera array, according to another embodiment.Images captured with unaligned read windows 130 in a multiple cameraarray have can significant decorrelation within the overlapping portionsof the captured images. Aligning the read windows 130 within the imagesensor capture windows 140 of a multiple camera array can increase thecorrelation between overlapping portions of captured images, thusbeneficially improving performance when stitching together adjacentimages as described further herein below.

To align the read windows 130 within a multiple camera array, an objectof interest can be identified. For instance, if a multiple camera arrayis used to capture a set of images (one per camera) of a garden, agarden flower within the images can be selected. A set of correlationcoefficients representative of an amount of decorrelation within theoverlapping portions of the captured set of images is determined. Theset of correlation coefficients can be weighted such that correlationcoefficients associated with the identified object of interest areweighted more heavily than other correlation coefficients. In someembodiments, correlation coefficients associated with a center regionrepresentative of an overlap between each of the images in the set ofimages are weighted more heavily. In some embodiments, the further awayfrom the object of interest or the center region a correlationcoefficient is, the less it is weighted.

The read windows 130 (such as read windows A, B, C, and D of FIG. 7B)are adjusted (moved within an image sensor capture window 140) such thatthe weighted set of correlation coefficients is lowest. In other words,the read windows 130 are re-located within the image sensor capturewindows 140, a set of correlation coefficients is determined for a setof images captured using the adjusted read windows 130 of a multiplecamera array, and if the resulting weighted set of correlationcoefficients is representative of less decorrelation, the adjusted readwindows 130 are selected over the previous read windows 130. In someembodiments, read windows 130 can be adjusted using a lookup table orfunction describing a relationship between correlation coefficients andread window location/adjustment. In some embodiments, instead of using aset of correlation coefficients, other representations of correlationwithin overlapping read window portions can be used such that a minimumor near-minimum entropy can be determined in response to the iterativeadjusting of read windows as described herein

This process can be repeated a number of times, for instance, until thecaptured images represent a below threshold level of decorrelation. FIG.7C illustrates aligned read windows 130 A′, B′, C′, and D′ within imagesensor capture windows 140 of a multiple camera array, according to oneembodiment. In some embodiments, read windows 130 are adjusted until theline of sight of each lens in a multiple camera array converges at adistance d determined to result in an optimal level of correlationbetween a captured set of images. FIG. 7D illustrates a distance ofoptimal correlation between image sensors of a multiple camera array700.

FIGS. 8A-8C illustrates a read window adjustment for each image sensorin a multiple camera array for convergence point adjustment, accordingto one embodiment. A plurality of read windows 130 of image sensorwindows 140 in a camera array 800 and a corresponding convergence point820 based on a distance 825 of a shift of the read windows areillustrated in FIGS. 8A-8C. As illustrated in FIG. 8A, the camera array800 includes a left camera 805A and a right camera 805B that capture animage 810A of the right side of a shared view 115 and an image 810B ofthe left side of the shared view 115. The substantial center 815 betweenthe cameras 805 results in a substantial center of a portion of sharedfields of view of the captured images 810A and 810B, as shown in thevertical dotted lines 815. Both captured images 810A and 810B capture acube seen by both cameras 805A and 805B within the shared view 115.

When capturing the shared view 115, the distance between the center ofthe lenses of the cameras 805A and 805B affect the convergence point 820of the lenses of the cameras 805A and 805B. This distance between thecenter of the lenses can be increased and decreased by shifting the readwindows 130 of the image sensor windows 140 within the cameras 805A and805B, as illustrated in FIG. 8A-8C. Thus, the distance 825A of theportion of the shared fields of view between the cameras 805A and 805Bin the read windows 130 affects the distance between the center of thelenses of the cameras 805A and 805B and results in a convergence pointat 820A.

For example, as the distance 825 increases, as seen in distance 825B inFIG. 8B, the distance between the center of the lenses of the cameras805A and 805B decreases, because the distance between the read windowsdecreases, and results in a convergence point at 820B behind the object,farther from the camera array 800. As the distance 825 decreases, asseen in distance 825C in FIG. 8C, the distance between the center of thelenses of the cameras 805A and 805B increases, because the distancebetween the read windows increases, and results in a convergence pointat 820C in front of the object, closer to the camera array 800.

In various embodiments, the distance between the read windows canincrease or decrease from shifting one or both of the read windows ofthe image sensors of the cameras 805A and 805B. The shift of the readwindows can be done automatically based on object detection algorithmsor by a manual input of a user using the camera array 800. For example,a user can input a setting or a mode (e.g., landscape, portrait, macro,sports, night, movie) and based on the input the read windows areshifted to better capture an image of that type of mode.

Image Processing & Taping

FIG. 9A illustrates a set of images captured by cameras in a 2×2 cameraarray, according to one embodiment. For example, the camera array 300 ofFIG. 3 collectively captured a shared view 115, the camera 105A capturedimage 910C, the camera 105B captured image 910D, the camera 105Ccaptured image 910A, and the camera 105D captured image 910B. Forpurposes of discussion, the image processing steps discussed herein willbe discussed in the context of the image 910A captured by the camera105C. However, the image processing steps are also performed in the sameorder on the other images 910B, 910C, and 910D. In another embodiment,the image processing steps applied to the images can be different thanthe image processing steps described herein, or can be performed in adifferent order on the other images 910B, 910C, and 910D.

The images captured by the camera array can vary in distortion and warpbased on the camera in the camera array or the position of the camera inthe camera array (e.g., roll, pitch, yaw, etc.). Thus, as seen in image910A, if the camera is a fish eye camera, the captured image 910A has afish eye distortion. In addition, the portions of the shared field ofview of image 910A are angled at a different orientation than adjacentimages 910B and 910C, as each image was captured at different angledfields of view. Since the images 910A, 910B, 910C, and 910D are of ashared view and each image shares a portion of a shared field of view920 with an adjacent image, common objects, such as objects 930, arevisible in the portions of the shared field of view 920. For example,the common object 930AB between 910A and 910B is in the portion of theshared field of view 920AB, the common object 930AC between 910A and910C is in the portion of the shared field of view 920AC, the commonobject 930BD between 910B and 910D is in the portion of the shared fieldof view 920BD, and the common object 930CD between 910C and 910D is inthe portion of the shared field of view 920CD. Thus, each image has afirst portion representative of an overlapping field of view with acorresponding portion of a horizontally adjacent image and a secondportion representative of an overlapping field of view with acorresponding portion of a vertically adjacent image. In the exampleshown, each common object 930 is warped differently in each adjacentimage due to the fish eye distortion.

FIG. 9B illustrates the captured images of FIG. 9A aligned based on theoverlapping portions, according to one embodiment. Following the examplefrom before, the common objects 930 are supposed to be vertical andhorizontal straight lines but are warped due to the fish eye distortion.Therefore, since the common objects 930 are supposed to be straight or,in general, since the shapes of the common objects 930 are known, thecaptured images of FIG. 9A (illustrated in the dotted line around image910A) can be processed, as illustrated in FIG. 9B, so that commonobjects 930 are aligned between adjacent images (in other words, so thatcommon objects 930 have the correct orientation and shape betweenadjacent images). The alignment can be performed by a warp function orany other suitable image processing algorithm that stretches the imagein a manner that results in the common object 930 being aligned in shapeand orientation between adjacent images. In one embodiment, the warponly straightens the common objects 930 or corrects distortion of thecommon objects 930 and regions near the common objects 930 while leavingthe outer edges farther from the common objects in their distortedstate. In the embodiment shown here, the warp is performed not locallybut on the entire image 910, resulting in correction of the commonobjects 930 and warping of the outer edges of the images 910.

FIG. 9C illustrates the aligned images of FIG. 9B cropped to removeexcess portions not horizontally or vertically aligned withcorresponding adjacent images, according to one embodiment. The alignedimages (illustrated in the dotted line around image 910A) are cropped(such as the image 910A) along the x-axis and y-axis of the image at theouter edges of the four images 910A, 910B, 910C, and 910D, resulting ina cropped image with at least 2 straight edges (as illustrated in eachof the images in FIG. 9C). In other words, for each image, portions ofthe image that are not both horizontally and vertically aligned withportions of the image representative of shared fields of view withadjacent images are cropped.

FIG. 9D illustrates the cropped images of FIG. 9C warped to correct fordistortions based on the alignment, according to one embodiment. Forexample, when the aligned images are warped to straighten out the commonobjects 930, the outer edges of the aligned images are also warped. Themagnitude of the warping to correct for distortions here is based on adistance of the portion to the first portion of the image and the secondportion of the image, wherein the magnitude of the second warping of afirst portion of the image representative of a shared field of view withan adjacent image and a second portion of the image representative of ashared field of view with an adjacent image is substantially 0. In anembodiment where only the regions near the common objects 930 arewarped, there is no need for correcting distortions of the croppedimages of FIG. 9C.

In general, the distortions corrected are the distortions caused by thealignment step from FIG. 9A to 9B. Therefore, if there are nodistortions to correct after alignment, this step is not required.Following the example illustrated, however, the outer edges of thealigned images are warped during alignment and, therefore, thedistortions of the outer edges are corrected here using warp techniquesand other transforms. In general, any image processing algorithm thatperforms the function of correcting for distortion can be performedhere. The image processing algorithms performed here, however, may notaffect the common objects 930. In this example, the common object 930 isa line and, therefore, the image processing algorithms performed here tocorrect for distortions do not warp the common objects 930 and thecommon objects 930 are still linear in shape after the images 910 arecorrected for distortions.

FIG. 9E illustrates the corrected images of FIG. 9D cropped to removeexcess portions and overlapping portions, according to one embodiment.The excess portions on the outer edges of the images 910 are removed aswell as the overlapping portions of shared fields of view. Then, a finalimage of the shared view being captured by the camera array is generatedby taping each cropped image to a horizontally adjacent cropped imageand a vertically adjacent cropped image. In other embodiments, theoverlapping portions of the corrected images of FIG. 9D aresubstantially reduced and each image is concatenated with eachcorresponding horizontally and vertically adjacent cropped image.

Additional Embodiments

FIG. 10A illustrates a distance between two lens modules in a multiplecamera array, according to one embodiment. The lens modules 1000A and1000B have some distance D between the centers of the lenses. Thedistance between the lenses results in a parallax error, which must becorrected for when stitching together images captured in a multiplecamera array. Parallax error is introduced even when the lens modulesare placed very close together, for instance 5 mm or less.

To help reduce or eliminate parallax error, a single lens can be usedfor multiple cameras in a multiple camera array. In some embodiments,the common lens is a ball lens. FIG. 10B illustrates a ball lens for usein a multiple camera array, according to one embodiment. The ball lens1002 is used for both lens module 1000A and 1000B. It should be notedthat although only two lenses are illustrated in the embodiment of FIG.10B, a common lens (such as the ball lens 1002) can be used for any orall of the cameras in a multiple camera array, such as all 4 cameras ina 2×2 camera array.

The optical paths of light through the ball lens 1002 and upon each lensmodule 1000 intersects within the ball lens 1002. Accordingly, thedistance D between the centers of the lenses is reduced to zero,effectively eliminating parallax error. It should be noted that in someembodiments, a ball lens 1002 introduces distortion to images capturedusing a ball lens 1002; in such embodiments, an additional warp functioncan be applied to each image captured using the ball lens 1002 prior tostitching the images together to reduce the effects of the distortionintroduced by the ball lens 1002.

FIG. 11A illustrates a camera body 1100 configured to receive and securea multiple camera array module 1110 in a plurality of configurations,according to one embodiment. The camera body 1100 can include cameracircuitry, interfaces, and the like (not shown) configured to provide acamera interface to a user of the camera body 1100. The camera body 1100includes a cavity 1105, for instance on the front surface of the camerabody 1100, configured to receive a multiple camera array module 1110 inany of a number of configurations.

FIG. 11B illustrates a multiple camera array module 1110 for insertionwithin a camera body 1100 in a plurality of configurations, according toone embodiment. The multiple camera array module 1110 (e.g., 2×2 cameraarray) includes 4 cameras 1115A-D coupled together to form asubstantially rectangle shape, with two protrusions extending away fromthe camera array module 1110 along the midpoints of two adjacent sidesof the multiple camera module 1110. In other embodiments, the cameraarray module 1110 can be in a substantially circular shape with similarprotrusions. The cavity 1105 of the camera body 1100 can includereciprocal cavities arranged to accommodate the protrusions of themultiple camera array module 1110 in any number of configurations. Inanother embodiment, the camera array module 1110 can include flexiblematerial where the protrusions are and the cavity 1105 of the camerabody can include protrusions instead of reciprocal cavities. Thus, theprotrusions of the cavity 1105 can snap into the flexible materialpresent in the camera array module 1110.

In the embodiment of FIG. 11A, the cavity 1105 within the front face ofthe camera body 1100 can receive the multiple camera module 1110 in theposition illustrated in FIG. 11B, and can further receive the multiplecamera array module 1110 in a position rotated 90 degrees clockwise.Such a configuration beneficially allows a user to capture images in afirst orientation of the camera body 1100, and to remove, rotate, andre-insert the multiple camera array module 1110 into the camera body1100 in a second orientation. In an alternative embodiment, the camerabody 1100 can be rotated while in the camera body 1100. For example, thecavity 1105 can include a reciprocal cavity path carved out inside thecamera body 1100 along the edges of the cavity 1105. Then, when thecamera array module 1110 is inserted in the cavity 1105, the cameraarray module 1110 can be rotated when the protrusions of the module 1110align with the reciprocal cavity path inside the camera body 1100.Although a particular embodiment is illustrated in FIGS. 11A and 11B, inpractice any configuration of camera body 1100 reciprocating cavity 1105and multiple camera array module 1110 can be used according to theprinciples described herein.

FIG. 12A illustrates a camera strap 1200 including a battery system andan associated electrical interface, according to one embodiment. In theembodiment of FIG. 12A, a camera strap 1200 includes one or morebatteries (e.g., 1210A, 1210B, 1210C, and 1210D) electrically coupled toand configured to provide power to a camera system coupled to the strapby strap wiring 1205 within the strap 1200. For example, the camerastrap 1200 can include battery interfaces 1215A, 1215B, and 1215C thatcan each receive a battery 1210 and electrically couple the battery 1210with the other batteries 1200 through the wiring 1205, as shown in FIG.12B.

FIG. 12B illustrates the camera strap 1200 of FIG. 12A, according to oneembodiment. The strap 1200 includes multiple layers: two outerprotective layers 1200A and 1200D, a battery layer 1200B configured toprovide power to a battery, and a circuit layer 1200C including one ormore circuits (not shown) configured to perform various functions, suchas a circuit configured to identify an amount of power stored by thebattery, an amount of power available to the camera, and the like. Thecamera strap 1200 can be coupled to the camera array through aconnection interface aligned with the wiring 1205 or with the batteryinterfaces 1215. In other words, the camera strap can secure a camera ora multiple camera array to a user, and the batteries 1210 can providepower to the secure camera or multiple camera array via the wiring 1205.

FIG. 13 illustrates a grip system for a camera system, according to oneembodiment. The rear view 1300A of the camera system illustrates therear of the camera. The top view 1300B illustrates a grip pattern on oneside of the top of the camera system. The grip pattern illustratedwithin the embodiment of FIG. 13 includes asymmetrical sawtoothgrip/friction protrusions angled in an obtuse relation to the body inthe direction of anticipated grip slippage by a user of the camerasystem. The grip patterns can be less than 0.5 mm in depth, and within0.25 mm apart in some embodiments. The front view 1300C illustrates twogrip areas on one side of the front of the camera. Each grip areaincludes sawtooth protrusions angled in different directions, andextending various lengths across the front of the camera system. Thedifferent angles of the sawtooth protrusions account for differentdirections in expected grip slippage; for instance, the top grip areacan be angled to accommodate grip slippage by a front of an indexfinger, and the bottom grip area can be angled to accommodate gripslippage by a side of a middle finger. The bottom view 1300D illustratesa grip pattern on one side of the bottom of the camera system, and theside view 1300E illustrates a grip pattern on one portion of the side ofthe camera system. The grip system illustrated in the embodiment of FIG.13 beneficially increases the ability of a user to grip a camera, forinstance in inclement conditions such as camera operation in cold andwet conditions. The position of the grip pattern on the camera systemalso beneficially guides a user's hand to a portion of the camera thatdoes not interfere with camera buttons, interfaces, and the like, anddoes not obfuscate the camera lens.

FIG. 14A illustrates adjacent lens stacks in a multiple camera array,according to one embodiment. Each lens stack, lens stack 1400A and lensstack 1400B, includes a stack housing 1402 containing one or more lenses1404. Each stack housing 1402 is shaped such that walls or outersurfaces of the housing converge from the rear of each lens stack 1400to the front. For example, the outer layer of the stack housing 1402 canbe less than 5 mm from the inner components including the lenses 1404.Accordingly, the lenses 1404 in each lens stack 1400 have progressivelysmaller diameters from the rear of each lens stack 1400 to the front.Each lens 1404 in the embodiment of FIG. 14A can be a disc lens, a flatlens, or the like. It should be noted that although certain lenses arereferred to herein as “disc lenses” or “flat lenses”, it should be notedthat in practice such lenses can have curved front and/or rear faces,but that the diameter of such lenses is generally larger than thefront-to-rear thickness of such lenses. The parallax error betweenimages caught using the lens stacks 1400A and 1400B is dependent on thedistance Δ between the center of each forward-most lens of lens stack1400A and 1400B. As the distance Δ decreases, the parallax error inimages captured by the lens stacks 1400A and 1400B decreases.

FIG. 14B illustrates adjacent lens stacks 1410 including cone lenses1414 in a multiple camera array, according to one embodiment. Each lensstack 1410A and 1410B includes a plurality of lenses: one or more disclenses 1412, and one forward-most cone lens 1414. As used herein, a conelens 1414 refers to a lens with a circular cross-section and a variablediameter, such that a diameter of a cross-section at the rear of thecone lens 1414 (the side facing the rear side of the lens stack) islarger than a diameter of a cross-section at the front of the lens (theside facing the front side of the lens stack). It should be noted thatalthough the cone lenses 1414 of FIG. 14B are shown with curved frontand rear faces, in practice these faces may be flat, or may be curved toa much lesser extent than as shown in FIG. 14B.

The use of cone lenses 1414 as forward-most lenses in the lens stacks1410 in the multiple camera array of FIG. 14B allows the housing 1402 ofeach lens stack 1410 to extend further forward in comparison to the lensstacks 1400 of FIG. 14A. This in turn reduces the distance Δ between thecenters of the forward-most lenses, which in turn reduces the parallaxerror in images captured by the multiple camera array. It should benoted that although only two lens stacks 1410 are illustrated in theembodiment of FIG. 14B, in practice, multiple camera arrays can includeany number of lens stacks, each including a cone lens as theforward-most lens within the lens stack.

It should be noted that the multiple camera arrays described herein canbe configured to couple to and act as a remote control for any deviceconfigured to wirelessly communicate with the multiple camera arraydevice. For instance, the multiple camera array can be configured to actas a remote control for another camera, a music/video playback device, astorage device, a wireless communication device, a telemetry monitoringdevice, a calendar control or display device, a slideshow controldevice, or any other wireless device.

Additional Configuration Considerations

Throughout this specification, some embodiments have used the expression“coupled” along with its derivatives. The term “coupled” as used hereinis not necessarily limited to two or more elements being in directphysical or electrical contact. Rather, the term “coupled” may alsoencompass two or more elements are not in direct contact with eachother, but yet still co-operate or interact with each other, or arestructured to provide a thermal conduction path between the elements.

Likewise, as used herein, the terms “comprises,” “comprising,”“includes,” “including,” “has,” “having” or any other variation thereof,are intended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus.

In addition, use of the “a” or “an” are employed to describe elementsand components of the embodiments herein. This is done merely forconvenience and to give a general sense of the invention. Thisdescription should be read to include one or at least one and thesingular also includes the plural unless it is obvious that it is meantotherwise.

Finally, as used herein any reference to “one embodiment” or “anembodiment” means that a particular element, feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. The appearances of the phrase “in oneembodiment” in various places in the specification are not necessarilyall referring to the same embodiment.

Upon reading this disclosure, those of skill in the art will appreciatestill additional alternative structural and functional designs asdisclosed from the principles herein. Thus, while particular embodimentsand applications have been illustrated and described, it is to beunderstood that the disclosed embodiments are not limited to the preciseconstruction and components disclosed herein. Various modifications,changes and variations, which will be apparent to those skilled in theart, may be made in the arrangement, operation and details of the methodand apparatus disclosed herein without departing from the spirit andscope defined in the appended claims.

What is claimed is:
 1. A multiple camera system, comprising: a sphericalfront lens; and a set of cameras, each camera comprising an image sensorand a plurality of lenses enclosed within a lens module, each lensmodule comprising a first width at a front of the lens module and asecond width greater than the first width at a rear of the lens module,each of the set of cameras configured to abut the spherical front lensand to capture an image representative of light passing through thespherical front lens, through the plurality of lenses of the camera, andincident upon the image sensor of the camera, the set of camerasconfigured to synchronously capture a set of images.
 2. The multiplecamera system of claim 1, wherein the set of cameras comprises twocameras arranged in a 2×1 camera array.
 3. The multiple camera system ofclaim 1, wherein the set of cameras comprises four cameras arranged in a2×2 camera array.
 4. The multiple camera system of claim 1, furthercomprising a housing configured to at least partially enclose thespherical front lens and the set of cameras.
 5. The multiple camerasystem of claim 1, wherein for at least one camera, for every pair oflenses within the plurality of lenses, a diameter of the lens within thepair of lenses closest to the front of the lens module is less than thediameter of the other lens of the pair of lenses.
 6. The multiple camerasystem of claim 1, wherein the set of cameras is configured tosynchronously capture the set of images in response to an input.
 7. Themultiple camera system of claim 6, wherein the input is provided by amaster camera of the set of cameras.
 8. The multiple camera system ofclaim 6, wherein the input is provided by an entity external to themultiple camera system.
 9. The multiple camera system of claim 1,wherein two cameras of the set of cameras have an overlapping field ofview.
 10. The multiple camera system of claim 1, wherein every pair ofcameras within the set of cameras have an overlapping field of view. 11.The multiple camera system of claim 1, wherein a parallax error betweeneach pair of adjacent cameras within the set of cameras is substantiallyzero.
 12. The multiple camera system of claim 1, wherein the set ofimages is provided to an image processor configured to apply a warpingfunction to each image to produce a set of warped images, the warpingfunction based on a distortion caused by the spherical front lens. 13.The multiple camera system of claim 12, wherein the image processor isfurther configured to stitch the set of warped images together toproduce a stitched image.
 14. The multiple camera system of claim 13,wherein the set of warped images are stitched together based on portionsof the set of warped images representative of overlapping portions offields of view of the set of cameras.
 15. A multiple camera system,comprising: a spherical lens; and a set of cameras abutting thespherical lens, each camera comprising an image sensor and acorresponding set of one or more lenses, the set of cameras configuredto synchronously capture a set of images, each image of the set ofimages representative of light incident upon an image sensor via thespherical lens and the corresponding set of lenses.
 16. The multiplecamera system of claim 15, wherein the set of cameras comprises twocameras arranged in a 2×1 camera array.
 17. The multiple camera systemof claim 15, wherein the set of cameras comprises four cameras arrangedin a 2×2 camera array.
 18. The multiple camera system of claim 15,wherein every pair of cameras within the set of cameras have anoverlapping field of view.
 19. The multiple camera system of claim 15,wherein a parallax error between each pair of adjacent cameras withinthe set of cameras is substantially zero.
 20. The multiple camera systemof claim 1, wherein the set of images is provided to an image processorconfigured to: apply a warping function to each image to produce a setof warped images, the warping function based on a distortion caused bythe spherical lens; and stitch the set of warped images together toproduce a stitched image based on portions of the set of warped imagesrepresentative of overlapping portions of fields of view of the set ofcameras.